Google PCA Manage and provision cloud infrastructure Practice Question
Your company runs a critical application on Compute Engine instances in us-central1. The application requires low latency between instances that are all in the same region. You notice that network latency between instances varies and sometimes spikes. You want to ensure consistent low-latency communication. You currently use external IP addresses for communication between instances. What should you do?
⚠ Common exam trap
Watch out — candidates often assume moving to the same zone or upgrading machine types will fix latency, but the root cause is the external IP routing path, not proximity or bandwidth.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use internal IP addresses instead of external IPs for inter-instance communication.
Using internal IP addresses (RFC 1918) for inter-instance communication avoids the overhead of NAT, external routing, and potential egress bottlenecks. Traffic stays within Google's internal network fabric, reducing latency variability and eliminating spikes caused by external internet path fluctuations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Move instances to the same zone to reduce network hops.
Why it's wrong here
Instances in the same zone can use internal IPs, but the key issue is using external IPs; moving to the same zone may not help if external IPs are still used, and it reduces fault tolerance.
- ✗
Upgrade to larger machine types to improve network bandwidth.
Why it's wrong here
Machine type size changes vCPU and memory, not the path packets take; latency spikes from external IP hairpinning persist. Larger types would be correct when the bottleneck is per-instance network bandwidth or processing capacity, not routing.
- ✓
Use internal IP addresses instead of external IPs for inter-instance communication.
Why this is correct
External IP traffic between instances traverses Google's edge network and public routing, adding variable hops that cause latency spikes. Internal IP addresses stay on the regional VPC network, giving direct, consistent paths between instances in us-central1 and satisfying the consistent low-latency requirement.
- ✗
Set up a Cloud VPN connection between instances.
Why it's wrong here
Cloud VPN encrypts traffic over the public internet through VPN gateways, adding encapsulation and internet-path jitter rather than removing it. It is the right choice for connecting on-premises networks or VPCs securely, not for intra-region instance-to-instance latency.
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Google Cloud Compute Options Overview
Key term
Compute Engine
Compute Engine is Google Cloud's Infrastructure-as-a-Service (IaaS) offering that lets you create and run virtual machines on Google's infrastructure.
Key term
Latency
Latency is the time delay between a request being sent over a network and the response being received, often measured in milliseconds.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCA practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCA exam.